Electric-switch-actuating mechanism



April 14, 1925.

H. P. MOCOLL ELECTRIC SWITCH ACTUATING MECHANISM Filed Aug. 21, 1922Patented Apr. 14, 1925.

W star-es i. er i i HENRY PERCY 'MGCOLL, T1 'MELBU'URNE, VICTORIA,AUSTRALIA.

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Application lna August 21, less. semi in. season.

W The present invention has been devised primarily to provide asimplified form of actuating mechanism for a pendant or pull cordelectric switch, but its application is not restricted thereto as theactual meniher controlled by the hand may be a rod or other mechanicaldevice capable of transmitting motion.

The invention'does however refer. specifically to'switchingineans whichat each successive actuation or impulse effects reverse movement of theswitch arm. that is'to sajgit the first actuation eii ects closure titthe switch the next following actuation operates to open the switch,

Briefly stated the essential features of this invention comprise apivoted switch arm actuated in one direction loytemporary engagementwith a floating draw bar the force of which latter is applied to the armat a point located at o'neside of the axis of the arm. I

Said floating draw liar follows the movement of the switch arm and whenthe force applied to the bar is removed it is mm matically returned byspring action and positions itself to again temporarily engage with theswitch arm but the force applied to the letter at the next Operation ofthe switch is at point located at the opposite side 01": the axis of thearm to that operated upon by the previous switch actuation.

The accompanying drawings illustrate a practical form of the invention,

Fig. 1 being a vertical section through the switch actuation mechanism,and

Fig. 2 a similar View showing the draw bar pulled down and heldtemporarily in such position by hand.

Fig. 3 is an underside plan of Fig. 1 with the cover removed.

Fig. i is an enlarged plan and 5 a side elevation of the switch arm.

Fig. 6 is an enlarged tacelview, and

7 an edge view of the draw bar. ,2 8 and Fig. 9 are elevations at rightto each other of the metal frame of shaped with Ithe mechanism theformer figure showing the switch arm in section. According-totheseillustrations the pivoted switch arm S consists ofduplicateliatpieces 1, 1 oined by transverse pins 2, 3 at equal radialdistances from andon'opposite sides of the pivotal centre at of saidarm, and it will he noted that the angle contained be tween line drawn"from each of said pins to v said centre approximate y degrees.

The piecesli, l are n ounte "on pivots fixed or screwed in'tlie sidemembers 5 a metal :tram'e l which memes-res, 5 are joined at the top andbottom hy eylindica'l ends 6 "r". Theitornierend 6 hasa central openinginternally screw threaded 'a's'at 8 l to engage the external threads ofa shouldered hollow screw 9 dropped intoa hole 10 termed in theporcelain cylindrlcal block 11 and the end *4" has also a central oening 12 and is externally screwed to engage the cover 27. y

The draw bar l) is approximately Y- a central recess 14} anttits prongs15 are torined'w'ith hooks 17, 18 with sloping noses 81 and said drawbar is locatcd in the centre o'tthe frame Fiend slides vertically in aslot 19 ot a transverse igiiide 20 joined to the side members 5, 5 ofthe frame, said guide having bevelled edges 21. v A spring is connectedat one end with the shank 23 of the draw bar-and at its other end withthe screw 9 as for instance hy inei is of transverse pin 24 passedthrough a loop at the top of the spring, said pin being seated in thediagonal nicks formed in the top of the screw. To the lower end otthedaw bar is attached a pull cord which passes through the opening 12 otthe frame F, and a coincident guiding orifice 26 formed in the cover 27which is screwed on to the end T of the frame and encloses themechanism. Connected with one side piece 1 oil the switch arm S at thepoint 28 is the lower end of a spring 29 attached at its upper end tothe upper end of the frame, said spring maintaining the switch arm inone or the other oi its two posit-ions according to which side of thevertical plant through the pivot 4: the lower end oi the spring ispositioned. By reference to Figs. 1 and 2 it will be seen that accordingto -whether the switch 3 is in the closed or open position (in the caseof aone way switch as illustrated in iiull lines inthe drawings) one orother of the pins 2, is nearer to the vertical plane through the pivotof the switch than the other consequent upon the angular relationship ofthe pins to said plane as illustrated and that one of said pins isalways in the path of one of the hooks 17 or 18 of the draw bar 1). Itis to be noted that said draw bar being loosely suspended by the spring22 and connected with the cord is free to sway edgewise in the guideslot 19 and is therefore a floating element and as the draw bar ispulled down from the position shown in Fig. l the hook 17 engages pin2.The switch arm is then caused to swing down on its pivot d and interruptthe circuit at contacts G and as the hook 17 is in engagement with thepin 2 the draw bar is drawn sideways as in Fig. 2 until spring 29 byreason of its lower end arriving on the opposite side of the verticalcentre of the pivot 4 retains the switch arm in the position shown insuch figure and the draw bar becomes disengaged from the pin 2 of saidswitch arn During this action the side sway movement'of the draw barpermits its other hook 18 to pass pin 3 which is now closer to thevertical plane of the pivot 2 and'actually in the path of hook 18 butwhen the cord 25 is released spring 22 returns the draw bar to normalposition and as it moves vertically the sloping nose 31 of hook 18contacting with the pin 3 causes the draw bar to again move slightly tothe right as in Fig. 2 so that hook 18 passes on the inner side of thepin 3 and eventually assumes the equivalent position of the hook 17 inFig. 1 ready to reverse the switch arm when the cord 25 is again pulled.Thus the alternate pulls on the cord makes and breaks the circuit ofcontacts C. n

It will be appreciated from the foregoing that in the practicalapplication illustrated it is essential to provide means such as theorifice 26 to maintain the correct alignment of the draw bar D.

In the case of a throw-over switch ad ditional contacts C are providedin the block 11 and an extension arm 80 added to the pieces of theswitch arm S as shown in broken lines in Figs. 1, 2, 3, 4iand 5.

Thus the switch alternately makes contact with contacts C and C bysuccessive pulls of cord 25.

It is to be understood that the invention is not restricted to anyparticular construction of the floating and spring controlled draw barmentioned nor to the means employed to effect the temporary engagementstated betweensame and the switch arm as same may be varied to suitvarying requirements.

It will be appreciatedirom the foregoing that in its broadest form theinvention may be regarded as combining with a pivoted switch arm a drawbar operating alternately at opposite sides of the axial centre of theswitch arm so that successive actuations operate the arm in an oppositedirection, the arm being disengaged from the draw bar after thecompletion of each operating stroke.

I claim p 1. A pull cord electric switch comprising a pivoted switch armhaving a pin on each side of its pivot, a spring fixed to the arm midwaybetween said pins, a draw bar formed at each side with hooks havingsloping noses, and means to reciprocate said draw bar and retain itcentrally of the switch arm, whereby said hooks alternately engage thepins.

2. In a. pull-cord electric switch, a switch arm pivoted within theframe and formed of two side pieces joined by pins located one on eachside of the pivot of said arms, a

spring connecting the upper end of said arm with the upper end of theframe, a floating draw bar central of the frame and located in a slottedguide therein said bar being suspended by aspring and having a pullingelement attached thereto and said bar being formed on each side with ahook having a sloping nose.

- Dated this 18th day of July, 1922.

HENRY PERCY MCCOLL.

